Grip-handle switch for electric drills



March 17. 1925.

R. A. NORLING GRIP HANDLE SWITCH -FOR ELECTRIC DRILLS Filed Oct. '7, 1920 5 Sheets-Sheet l March l 7. l 925. 1,529,910 R. A. NORLING GRIP HANDLE SWITCH FOR ELECTRIC DRILLS Filed oct. v, 1920 :s'Sheets-sheet 2 @i 655mm@ March 17. 1925.

R. A. NORLING GRIP HANDLE' SWITCH FOR ELECTRIC DRILLS Filed Oct. '7, 1920 5 Sheets-Sheet 5 Patented Mar. 17, 1925.

UNITED STATES PATENT OFFICE.

REINHOLD 4A.. NORLING, OF AURORA, ILLINOIS. ASSIGNOR T0 INDEPENDENT PNEU- MATIC TOOL COMPANY, O'F CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

GRIP-HANDLE SWITCH FOR ELECTRIC DRILLS. y

Application led October 7, 1920. Serial'No. 415,331.

To all whom t may concern.'

Be it known that I, REINHOLD A. NoR- LING, a citizen of the United States, residing at Aurora, in the county of Kane and State of Illinois, have invented new and useful Improvements in Grip-Handle Switches for Electric Drills, vof which the following is a specification.

This invention relates to grip handle switches for portable electric drills and like tools, and consists in the matters hereinafter described and more particularly pointed out in the appended claims.

In the accompanying drawings- Fig. 1 is a longitudinal sectional view of an electric drill provided with al grip handle and switch mechanism embodying the features of my invention;

Fig. 2 is an enlarged sectional view of the handle, the switch mechanism associated therewith being shown in side elevation;

Fig. 3 is a transverse sectional view taken through the handle on the indirect line 3*3 of Fig. 2;

Figs. 4 and 5 are side eleva-tional views, with parts in section, and showing the turret turned into on and off positions, respectively.

Fig. 6 is an enlarged longitudinal sectional view taken through the turret;

Fig. 7 is aV transverse sectional view taken through the turret on line 7--7 of Fig. 6;

Fig. 8 is a sectional view taken through one of the bearings for the turret on line 8--8 of Fig. 3; and

Fig. 9 is a sectional view of a detail of construction and taken on line 9-9 of Fig.

The electric drill or tool shown in the drawings is of that type which may be readily 'picked up and be held in the hands of the operator while working with the tool 'and be easily carried or moved from one place of work to another.

The tool has an outside casing 1, iii which.

is located and housed the electric motor which turns the spindle of the tool. The motor has an armature shaft 2 extending lengthwise of the tool with its ends journaled in bearings in the drill casing 1. On .the shaft 2 is an armature 3 and a commutator 4, the former rotating in a field or stator 5 retained in the drill casing, as usual in electric drill construction of this general type. Electric current is supplied to the motor through an outside cable 6 containing conductor wires 7 and 8. The cable enters the casing 1 at one side through a hole in the casing and is secured to the casing by a clamp 9. The port-ion of the cable entering the casing and immediately outside of the same is wrapped with a coil of wire 10 to protectsuch portion of the cable from injury and direct it away from the drill so as not to be unduly in the way.

Secured to the forward end of the casing 1 is a gear case 11, in which is journaled the drill spindle 12. This projects beyond the forward end of the gear case and is there provided with a chuck or tool holder 13, as

in drills of this kind. The spindle 12 is offset laterally from the armature shaft 2, as shown, and the latter drives the former through a suitable gear train, as illustrated.

At the rear or opposite end of the drill case 1 is a handle 14, constructed in accordance with my invention. This handle has a. hollow body portion 15, shaped and open at one end to fit over and receive the adjacent inner end of the drill case 1, as shown in Fig. 1. The handle seats on a rib or shoulder 16 provided on the case 1, and the handle is detachably secured to the drill case by togglebolts 17, 18, one carried by the handle and the other by the drill case, the bolts being received in outwardly opening slots provided in the respective parts. Nuts are applied on the bolts to cla-mp the handle and drill case together. The handle body 15 has a rearwardly extending neck portion 19 at one side thereof, which joins the grip portion 2O of the handle with the body por-tion 15. This provides a passage-way between the free end of the grip portion 20 and the body portion 15, thus giving the handle an open grip.

The switch mechanism of my invention comprises a-iiat plate 21, as clearly shown in Fig. 3. This plate is secured by screws 22 to that end of the drill case 1 projecting into the hollow body portion 15 of the handle. The plate 21 is bifurcated at one side to provide two laterally spaced parts 23, to each of which is bolted a part 24 to provide split bearings for the rotary member or turret 25 of the switch mechanism, as

shown in Figs. 3 and 8. The turret 25 is made of fiber or other insulating material and is square in construction beyond said bearings. The portions of the turret in the bearings are cylindrical so that the turret may be turned about its longitudinal axis. Secured to the turret between the bearings isa ratchet 26 provided with four teeth. The ratchet'V is made in two parts applied about the turret in an annular groove an secured together and tothe turret by rivets 27, as shown in Fig. 7. For turning the turret, there is a pawl 28 pivoted at 29 to a plunger 30 slidably mounted in a bore in the neck portion 19 of the handle, as shown in Figs. 1 and 2. A flat spring 31 is rigidly secured at one end'to the plunger 30 and has its other end bearing against the pawl 28 to normally hold the pawl in the operative position shown in Fig. 1. The plunger 30 is slotted lengthwise to receive the pawl and its s ring, and surrounding the plunger is a coi ed spring 32 seating at one end on an annular shoulder in' the bore and bearing at its other end against a rib or shoulder on the plunger. In the construction shown,

the plunger 30 is cylindrical, and to holdv it against rotation and to limit its extent of sliding movement, there is a stop pin 33 in the bore and lixed to the handle. Thispin extends across an elongated slot 34 in said plunger. The ends of the slot when brought in contact with |the pin limit'the sliding movement of the plunger, and thus prevent the plunger when moved inward from turning the turret more than a trifle over oneeighth ofa turn, the ratchet teeth being ar# ranged accordingly. The pin also limits the .outward movement of the plunger by its spring 32, and thus prevents the plunger from being ejected out of its bore.

On eachside of the plate 21 is a pair of spring contact fingers, the fingers on one side of the plate being indicated by 35 and the ones on the opposite side by 36, as shown .in Fig. 3. The lingers are secured to the plate 21, and to accomplish "this the plate .has at each side an outwardly projecting flange or ear 37 on opposite sides o f which are blocks 38 of insu ating materlal" and against which the contact lingers are secured by bolts 39 in tubes40 (Fig. 9) also of insulating material. .The ingershave holes to allow the tubes to extend through them, and on the outside of each finger is a block 41 of insulating material and through which the tube vand bolt extend, as shown in Fig. 9. Each pair of lingers 35, 36 have their free ends spanning the adjacent portion of the turret 25 on the outside of the bearing thereof, and each linger carries a contact block 42 bearing against the portion of the turret therebetween, as shown in Figs. 4 and 5.

Such portions of the-.turret are square in cross-section and each has a hole boredthrough across the axis of the turret to recelve and hold a plug 43 made of brass or other material that will conduct an electric current. Each plug 43 extends clear through the turret and thus divides the end portion of the turret at the plug into two diametrically opposed iat sections 44,44, these being of insulating material. The contact blocks 42 are rounded, as shown, to enable the turd ret to be turned or rotated between them for bringing either the plugs 43 orthe insulated sections 44 into engagement With the blocks, as shown in Figs. 4 and 5, respec- /wire 48 with a terminal of the stator5. Se-

cured in like manner in contact with the other finger 36 is a terminal plate 49, to which is connected the supply wire 7, as shown in Fig. 1. Secured in like manner to one of the fingers 35 is a terminal plate 50, to which is connected the other supply wire 8. A contact strip 51 issecu-red in like manner to the other finger 35 and leads to the terminal of the brush holder 52, as shown in Fig. 2.

When the operator grasps theA grip portion 20 of the handle, the natural position of his hand is with his thumb free to readily reach and depress the plunger 30 without changing the position ofhis hand. To turn on the current to the' tool, all that he is required to do is to depress or force the plunger 30 inward with his thumb. This causes the pawl 28 to turn the turret 25 a trifle over an eighth of a turn.- This brings the blocks 42 just over the corner of the square, and the tension ofthe contact ingers 35, 36 will act to complete the turning of the turret a full quarter turn and cause the turret to snap into that osition, with the' blocks in contact with t e plugs 43, and complete the circuit. The blocks Iwill enter the shallow recesses in the.plugs, as shown in Fig. 4. By releasing the plunger 30, it will be returned to its starting position by its spring 32, and on the return, the pawl 28vwill slip over the next tooth of the ratchet 25 to be in position to turn the turret again to cut 'oil the current; When the plunger 30 is again depressed, the turret is turned in the same manner andthe blocks 42 brou ht into contact with the'sections 44 of t e turret, as shown inFig. 5, and the current to the mo tor cuto. Thus, the current may be easily turned off and on by `depressing the plunger suiciently to cause the lingers to act on the i gasping the handle being with the thumb at t e plunger 30, the switch mechanism may be operated tol turn the current on and off without moving the hand along or off the handle or releasing the grip thereon.

After the plunger has been depressed to tutn on the current, the plunger can be moved back and forth to a considerable extent without in the least interferin with the contact of the switch because the p unger does not turn the turret a full quarter turn, the stop pin 33 preventing. The only way to interfere with the connection is to let the plunger back to its full stroke.

Both of the supply wires 7 and 8 lead to the contact fingers and, as the switch is so constructed that both leads are broken when the current is turned ofi", there is no chance left for short-circuiting as no current is present in' the drill windings proper. This is a decided advantage because in connecting up a drill to the line there is no way of telling which one of the wiresis the positive one and by having the switch break the current through both wires the advantage noted must necessarily follow. 4

rlhe handle 14 having detachable connection with the drill casing 1 and the turret 25 and the contact fingers all being mounted on the drill casing, the handle may be removed from the drill casing without disturbing any of the connections between the switch mechanism and the supply wires and the contacts to the motor. These all being intact when the handle is removed makes it possible to run the drill with the brushes, commutator and all parts including the switch parts exposed for inspection.

The turret 25 is provided with integral flanges 53, 53, one inside of each bearing (23, 24) to hold the turret from shifting endwise.

The switch construction is positive in its action and substantial in its construction.

While I have shown and described herein i n detail a handle and switch mechanism embodying the features Gfmy` invention, it is of' course to be understood that the details of construction and arrangement of parts illustrated may be variously changed and modified without departing from the spirit and scope of my invention.

I claim as my invention:

l. The combination with an electric tool having a casing. of a handle having a hollow portion open to receive one end of the toolV casing and secured thereto, and a switch mechanism, including a switch member in the hollow portion of said handle and rotatably mounted on said tool casing, a spring pressed plunger in said handle and de. pressible from the outside thereof, and a pawl and ratchet connection between said plunger and switch member to turn said member by depressing said plunger for -tween the turret and said plungerl to turn the turret by depressing the plunger, spring contact fingers bearing against said turret, and contact plugs in said turret and brought into and out of contact with said fingers as the'turret is turned.

3. The combination with an electric tool having a casing, of a handle having a hollow portion open to receive one end of said tool lcasing and secured thereto, and a switch mechanism comprising a plate in the hollow portion of said handle and a turret of insuL lat-ing material rotatably mounted on said pla-te, said turret having square portions, spring contact fingers mounted on said plate and bearing against said square portions on opposite sides thereof, contact plugs in said square portions and brought into and out of contact with said fingers as the turret is turned, and means including a ratchet on the turret and a depressible plunger on the handle for turning said turret.

4. The combination with an electric tool having a casing. of a handle having an open grip and a hollow portion open to receive one end of the tool casing, means det-achably connecting said handle to said tool casing, and a rotary snap switch mechanism in the hollow portion of said handle and carried by said tool casing, and a spring pressed plunger in said handle and depressible from the outside thereof to operate said switch.

5. The combination with an electric tool having a casing, of a handle having an open grip and a hollow portion open to receivel one end of said tool casing, toggle bolfts detachably connecting said handle to said tool casing, and a rotary snap switch mechanism in the hollow portion of said handle and carried bv said tool casing, anda spring pressed plunger in said handle and depressible from thc outside thereof to operate :aid switch.

G. The combination with an electric tool having a casing, of a handle having a hollow portion open to receive one end of the tool casing and secured thereto, and a switch mechanism, comprising a turret m the hollow portion of said handle and rotatably mounted on said tool casing, a spring pressed plunger in said handle and depressible from the outside thereof, a pawl and ratchetconnection between said turret and plunger to turn the turret less than a predetermined portion of a complete turn upon each de pression ot said plunger, and spring contact fingers bearing against said turret on opposite sides and acting to impart a quick snap movement to the turret to complete the turn.

7. The combination with an electric tool having a casing, ot' a handle having a hollow portion open to receive one end ot said tool easing and secured thereto, and a switch mechanism, including a turret in the hollow portion o1V said handle and rotatably mounted on said tool casing, a spring pressed plunger in said handle and depressible from the outside thereof, a pawl and ratchet connection between said turretfand plunger to turn the turret less than a quarter of a turn upon each depression ot said plunger, andV means independent of said plunger for 1mpartmg a quick snap movement to sald turret to complete the quarter turn thereof and to turn the current to the tool on and oi on the turning of said turret.

8. The combination with an electric tool having a casing, of a handle having-"a hollow portion'open to receive the inner end of the tool casing and secured thereto, switch means for turning onand o the current to the tool, said switch means being located in the hollow portion of the handle between the latter and the tool casing and carried by one of the same, and means at the handle for operating said switch means.

9. The combination with an electric tool having a casing. of a handle having a hollow portion open to receive the inner end of the tool casing and secured thereto, switch means for turning on and oi the current to the tool, said means being located in the hollow portion of the handle between the. latter and the tool casing and being carried bv one of the same, and. means carried by the handle for operating said switch means.

10. The combination with an electric tool having a casing, of a handle having a hollow portion open to receive the inner end of the tool casing and secured thereto, a rotary snap switch for turning on and off the current to the tool, said switch being located in the hollow portion of the handle between the latter and the tool casing and carried by one of the same, and means carried by the handle for operating said switch.

11. rlhe combination with an electric tool having a casing, of a handle having a hollow portion open to receive the inner end of the tool casing and secured thereto. a. rotary snap switch for turning on and oil' the current to the tool, said switch being located in the hollow portion of the handle between the latter and said tool casing and carried by one of the same, a spring pressed plunger carried by said handle, and a pawl and ratchet connection between said plunger and switch for operating the latter by said plunger.

12. The combinationv with an electric tool having a casing, of a handle having a hollow portion open to receive the inner end of the tool casing and secured thereto, a switch mechanism for tunning on and oli' the current to the tool, said switch mechanism being located in the hollow' portion of the handle between the latter and said tool casing and carried by one of the same, said switch mechanism comprising a turret of insulating material with square portions, contact plugs therein, spring contact lingers carrying rounded contact blocks brought into and out of contact with said plugs as the turret is turned, and means carried by said handle for turning said turret.

13. The combination with an electric tool having a casing, of a handle having a hollow portion open to receive the inner end of the tool casing and being detachably connected therewith, switch means for turnin on and oi' the current to the tool, said switch means being located in the hollow portion of said handle and carried by said tool casing, alll wires for supplying current to the tool through the switch means being carried by said tool casing so that the han-- dle may be removed therefrom without disconnecting said wires, and means carried by said handle for operating said switch means.

14. The combination with an electric tool having a casing, of a handle having a hollow portion open to receive the inner end of said tool casing and being detachably connected therewith, a rotary snap switch for turning on and off the current to the tool, said switch being locatedin the hollow portion of the handle and carried by said tool casing, and means carried by the handle for operating said switch.

15. The combination with an electric tool having a casing, of a handle having a hollow portion open to receive the inner end of said tool casing and being securedthereto, switch means for turning on and oli' the current to the tool, said switch means' being located in the hollow portion of said handle and carried by said tool casing, said handle having a hand grip and a neck portion, the latter connecting the grip with said hollow portion and means carried by said neck portion for operating said switch.

16. The combination with an electric tool having a casing, of a handle having a hollow portion open to receive the inner end of the tool casing and secured thereto, switch means for turning on and olif the current to the tool, said switch means being located in the hollow portion of said handle between the latter and said tool casing and carried by one of the same, sa1d handle having a grip und a neck portwn? the latter @ancetlim l,

ing the grip with said hollow portion, a spring pressed plunger slidably mounted in said neck portion and depressible from the outside thereof, and means in the hollow portion of the handle between the plunger and switch means for operating the latter by said plunger.

17. An electric switch mechanism, comprising a support, a plate secured thereto, a. turret of yinsulating material rotatably moruited on said plate and having square portions, contact plugs in said square portions and exposed on opposite sides thereof, spring lingers mounted on said plate and spanning said square portions of said turret, rounded contact blocks carried by said iingers and brought into and out of contact with said plugs as the turret is turned, a ratchet carried by said turret, a spring pressed plunger adjacent said turret, a pawl carried by said plunger to turn said turret through the ratchet thereon, and a support for said plunger.

18. An `electric switch mechanism, comprising a support, a plate secured thereto and having spaced bearings, a turret of insulating material 'extending between said bearings and journaled therein, a ratchet secured to said turret between said bearings, said turret having square portions beyond said bearings, contact plugs in said square portions and exposed on opposite sides thereof, spring fingers spanning said square portions, rounded contact blocks carried by said fingers and being brought into and out of contact with said plugs as the turret is turned, a spring pressed plunger adjacent said turret, a pawl carried by said plunger to turn said turret through the ratchet thereon, and a support for said plunger.

19. An electric switch mechanism, comprising a support, a plate secured thereto andA terial extending between said bearings and journaled therein, a two part ratchet secured to said turret between said bearings, said turret having square portions beyond said bearings, contact plugs in said square portions and being exposed on op osite sides thereof, ears on opposite sides o? said plate, spring fingers secured at their inner ends to said ears and having their outer ends spanning said turret at the square portions thereof, rounded contact blocks carried by said lingers on the inside thereof to be brought into and out of contact with said plugs as the turret is turned, a spring pressed plunger adjacent said turret, a pawl on said plunger t'o turn said -turret through the ratchet thereon, and a support for said plunger.

20. A switch mechanism comprising a rotary turret, a support therefor, said turret having square portions carrying contact plugs exposed on opposite sides thereof, spring fingers on said support and spanning said turret at said plugs, rounded contact blocks carried by said fingers to be brought into and out of contact with said plugs in turning said turret, the contact faces of said plugs and turret being wider than the blocks and having depressions therein to receive said blocks, means for turning said turret, and a support for said means.

In testimony that I claim the foregoing as my invention, I aliix my signature, this 1st day of October, A. D. 1920.

REINHOLD A. NORLING. 

